Jet mill for titanium dioxide production line

The scientific name of titanium dioxide is titanium dioxide, the molecular formula is TiO₂, and the crystal form is anatase, rutile, and brookite. The plate-titanium type is an unstable crystal type and has no practical value in industry. The anatase type is stable under normal mixing, but will be transformed into rutile type at high temperature; rutile type is the extremely stable crystal form of titanium dioxide with compact structure.

At present, jet mills are used at home and abroad to complete the final product pulverization of titanium dioxide.

Why choose jet mill?

The jet mill can pulverize solid materials into sub-micron level, and the particle size distribution is very narrow, the pollution is small, and the pulverization process does not generate hot stars, and simple chemical reactions can be carried out in the jet mill. In comparison, the Raymond mill is not suitable for the crushing of titanium dioxide.

Know the jet mill

Jet mill, also known as fluid energy mill, is a device that uses the energy of high-speed airflow or superheated steam to make particles impact, collide, and rub each other to achieve ultrafine pulverization or deaggregation.

The compressed air/superheated steam enters the Laval nozzle, the air/steam accelerates into a supersonic airflow, and the high-speed jet moves the material at a high speed, causing the particles to collide and rub against each other and be crushed. The crushed material reaches the classification zone with the airflow. The materials with the required fineness are collected by the trap, and the materials that do not meet the requirements are returned to the crushing chamber to continue crushing.

Studies have proved that more than 80% of the particles are crushed by the impact control between the particles, and less than 20% of the particles are crushed by the impact control and friction between the particles and the wall of the crushing chamber.

Features: The product has fine particle size, narrow particle size distribution, and good particle shape dispersion; low-temperature pulverization without medium, no heat is generated during the pulverization process; the system is closed with less dust, low noise, clean and environmentally friendly production process; suitable for heat sensitivity, low melting point sugar and Crushing of volatile materials.

Which jet mill to choose?

There are five types of jet mills: counter-jet (collision) jet mills, circulating tube jet mills, fluidized bed jet mills, target jet mills, and flat jet mills.

In the production process of titanium dioxide, a flat type (also known as a horizontal disc type) jet mill is used for pulverization. Compared with other types of jet mills, it has the following advantages: the flat type (also known as the horizontal disc type) jet mill has a self-grading function, and organic additives can be added while pulverizing, which can organically modify the surface of the titanium dioxide. , It is beneficial to increase the dispersibility of titanium dioxide in different application systems.

Which grinding medium to choose?

Use superheated steam as the grinding working medium. Steam is easily available and cheap, and the pressure of the steam working medium is much higher than that of compressed air and is also easy to increase, so the flow energy of steam is greater than that of compressed air. Superheated steam has higher cleanliness than compressed air, low viscosity and no static electricity. At the same time of grinding, it can eliminate static electricity generated by collision and friction of materials, and reduce the phenomenon of secondary cohesion of powdered materials. Crushing under high temperature conditions can improve the application dispersibility of titanium dioxide and increase the fluidity of titanium dioxide. Low energy consumption, only 1/3-2/3 of compressed air.

As an important equipment for ultra-fine grinding, the jet mill plays an irreplaceable important role in the production of titanium dioxide. The development of jet grinding can basically meet the needs of titanium dioxide production, but the service life and crushing of the jet mill The effect still needs to be further improved, and the configuration and automatic control of the jet grinding system still need to be improved, and the high-efficiency jet grinding with large capacity still needs to be developed. With the development of science and technology and the application of new materials, jet mills will also play a more active role in promoting the development of the titanium dioxide industry.

Article source: China Powder Network